Diaminopyridine dyes for dyeing cellulose-containing fibers, particularly cellulose fibers and polyester-cellulose fibers in from orange to bluish red, with excellent fastness to light. The dyes are represented by the formula (I): ##STR1## X is a hydrogen atom, or a halogen atom; Y is an alkoxy group containing from 1 to 5 carbon atoms, --O--R.sup.10 --O--R.sup.11, or a phenoxy group; andn is 2 or 3, and wherein R.sup.1 is a nitro group, a cyano group, a methylsulfonyl group, a phenylsulfonyl group, a mono- or di-lower alkylaminosulfonyl group, an acetyl group, or a benzoyl group; R.sup.2 and R.sup.3 are each a hydrogen atom, a trifluoromethyl group, a halogen atom, or a cyano group; R.sup.4 is a hydrogen atom, a lower alkyl group, a mono- or di-lower alkylaminosulfonyl group, a mono- or di-lower alkylcarbamoyl group, or an acetylamino group; R.sup.5 and R.sup.6 are each a hydrogen atom, a halogen atom, or a lower alkyl group; R.sup.7 is a lower alkyl group; R.sup.8 is a hydrogen atom or a halogen atom; R.sup.10 is an ethylene group, or a propylene group; and R.sup.11 is a methyl group, or an ethyl group.